A thermoelectric device is able to directly convert heat (i.e. a temperature gradient) into electricity. If their efficiency may be increased and the operational temperatures reduced to near room temperature (300 K), thermoelectric devices may begin to supplement or even supplant traditional power sources used in wearable or internet of things (IoT) devices. High thermal conductivity with lower electrical conductivity may prevent higher efficiency. Unfortunately, there are no single materials that possess simultaneously higher electrical conductivity and lower thermal conductivity. Low efficiency and high operating temperatures, combined with higher cost, prohibit current thermoelectric devices from wider market adoption.
Low efficiency may relegate thermoelectric devices to a few applications where their simplicity and ruggedness may outweigh the inefficiency, such as sensors and waste-heat-energy converters. The current market products are often used in conjunction with either heat sink or active cooling at high temperatures for industrial use cases. Additionally, the current state of the art thermoelectric devices are rigid and bulky, and are produced using complex processes which scale poorly, resulting in higher cost. As a result, current thermoelectric devices, being expensive, inefficient near room temperature, rigid, and bulky, are less than ideal for use in wearable or internet of things (IoT) devices.